Congenital cardiovascular defects, specifically single ventricle abnormalities, constitute the most common cause of death among infants born with birth defects. Even after surgically rerouting the single ventricle circulation via the Fontan procedure, the circulation in these patients relies on blood flowing passively through the lungs. Thus, this group of patients is continually at risk for Fontan failure and its consequences. Thus, there is a need for a compact method to drive implantable ventricular assist devices used to re-energize blood flow in these patients. Over the last decade, our team has made advances in frequency rectification concepts that have yielded novel compact piezoelectric hydraulic pumps for morphing aircraft structures. While representing a significant advancement in aerospace, they have yet to be considered as drivers for mechanical circulatory support devices. It is our hypothesis that these new high power devices can be effectively used as miniature assist device driver for Fontan circulation. We propose to develop and evaluate a novel piezoelectric hydraulic pump driver tailored to re-energize blood flow to the lungs for patients with the Fontan circulation. It is our hypothesis that the piezohydraulic technology represents a novel approach to construct a miniaturized ventricular assist device driver for both pediatric and adult Fontan patients. The focus of this research is to experimentally demonstrate the ability of a piezoelectri pump to transfer power to the Fontan circulation and assist blood flow in Fontan patients. We plan to utilize the new piezoelectric hydraulic pump to drive a commercial short term circulatory support device and also a long term implantable device fabricated at UCLA. This device will be characterized in vitro to demonstrate that the system can increase fluid flow through the pulmonary circulation while reducing systemic venous pressure in a mock Fontan fluidic circuit. To date, mechanical assist device drivers small enough for pediatric patients are non-existent. The proposed effort will not only provide the opportunity for realization of a unique device to aid patients with the Fontan circulation, but it will also provide an outline for the use of compact hih power density piezoelectric devices for use as mechanical circulatory support drivers